EV conversions

[Mo Murphy]

Awesome Si, awesome !

Mo

[cackshifter]

16 hours ago, Mo Murphy said:

Awesome Si, awesome !

Mo

Absolutely! Terrific! Surprised you haven't made it fly supersonically and go underwater, maybe a job for next week?

[simonr]

1 hour ago, cackshifter said:

Absolutely! Terrific! Surprised you haven't made it fly supersonically and go underwater, maybe a job for next week?

🤣

[Ed Poore]

Probably has some flamethrowers left over from a film he worked on.

[cackshifter]

2 hours ago, Ed Poore said:

Probably has some flamethrowers left over from a film he worked on.

Probably quite difficult to implement without using fossil fuels.  

[miketomcat]

23 minutes ago, cackshifter said:

Probably quite difficult to implement without using fossil fuels.  

Plasma blast then. 

[FridgeFreezer]

On 9/23/2022 at 12:40 PM, simonr said:

I spent about £7.5k.  Batteries were £2k of that, for 13.5kWh.  For a regular vehicle (heavier than this, Actually Don Incol's Lightweight LR) a rule of thumb seems to be Pack kWh x 2.5 = Range in miles.

Based on being half the weight, but about the same drag coefficient, I'm betting on 50m+ range at 30mph & 30m range at 50mph.

So, for a 100m range in a Land Rover using new batteries, I would expect to pay about £15k for the bits.  If you use 'pre-loved' batteries and maybe a Nissan Leaf motor (which has been thoroughly hacked now, using a 'Thunderstruck' controller), a bit less maybe.

The main thing I would change is I were starting over would be to use pre-made battery modules.  The amount of extra thinking & construction that needs to go into making your own with heating, cooling & management - isn't worth it!

Thanks Si, that's good info and (perhaps unsurprisingly) feels like it's gotten a lot cheaper than whenever I last took a look at this sort of thing. ~15k to make a classic LR into a usable green-laning / sunny weekend sort of toy feels quite accessible especially with the values of old LR's going ever upwards.

It's very heartening that the EV conversion / reverse-engineering / aftermarket scene appears to be thriving and solving a lot of the problems very rapidly - I guess since it's all "just" electronics there's a lot of stuff that becomes a lot easier / is already well understood.

[Nonimouse]

was just reading the latest figures on EV V's petrol costs. The read this.  Cool ride though

[simonr]

5 hours ago, FridgeFreezer said:

I guess since it's all "just" electronics there's a lot of stuff that becomes a lot easier / is already well understood.

And you're probably better at that than me!

[FridgeFreezer]

16 hours ago, simonr said:

And you're probably better at that than me!

These days after spending all day doing it in the office I can't be ar5ed to spend all evening/weekend doing it as well! Quite nice to pick a spanner up instead

However, stuff being "only" electronics does mean it's all very possible in ways that big oily lumps aren't - an electric motor just needs the right volts at the right time to make it go, compared to the difficulties of trying to reverse-engineer a viable engine management system for a modern diesel it's ridiculously simple and very hard to damage if you mess it up. One 3-phase motor can be run very much the same as any other, controllers become a fairly simple universal device.

Plus a lot of the OE stuff just needs talking to nicely on the CANbus to be persuaded to play, and all the tools and methods are already out there for that.

DIY'ing battery charging on huge lithium packs still gives me some trepidation but as battery tech moves on the safety goes up and people learn how to do it properly / better BMS come along and it all gets easier and cheaper.

I seriously think the 2-door is going to end up going straight to electric by the time I get round to it.

[Arjan]

Very interesting read - thank you.

Apart from the obvious costs to convert a ICE to Electric, we face in France the legal problem.

At the moment it is next to impossible to get a DIY conversion on the road legally.

A few companies have a monopoly it seems to do the conversion and the price tag equals that of a new Defender...

 

[simonr]

3 hours ago, FridgeFreezer said:

DIY'ing battery charging on huge lithium packs still gives me some trepidation but as battery tech moves on the safety goes up and people learn how to do it properly / better BMS come along and it all gets easier and cheaper.

Me too!  But chargers are an off the shelf item, as is the battery management (and the two talk to one another) - so, these days it's pretty simple!

I've used LiFePO4 cells, mainly because they are the hardest to set fire to (or make spontaneously combust), the down-side being lower power density.  Probably worth it for the peace of mind!

[landroversforever]

Potentially silly question, probably aimed at @simonr..... Would it be possible to build lighter batteries to replace your usual pair of batteries? Or would the charging etc just make it silly complicated and no weight saving?

Edited to add that I'm meaning in a 'normal' non-EV truck with a winch or two or a big camping setup.

[Bowie69]

Common to use big LifePo4 batteries in overlanders/campers for the 'house' battery, and a BMS between them and the alternator.

The cost is always coming down, but last time I looked 100Ah was about £700. Of course that usable, lead acid 100Ah won't give you 100Ah usable.

They take a much higher charge current than lead acid, so once you drive they are full pretty quickly. It's not unknown to have 4-600Ah on some Aussie rigs, and using induction cookers instead of gas.

Not sure I would use one as a start battery though.

[simonr]

35 minutes ago, landroversforever said:

Would it be possible to build lighter batteries to replace your usual pair of batteries? Or would the charging etc just make it silly complicated and no weight saving?

There are more & more completely self contained LiFePO4 'car' batteries on the market.  You effectively get double the capacity compared to Lead Acid - so your 100Ah Lead Acid can be replaced by a 50Ah LiFePO4.  There's a significant weight saving even for the same Ah rating.

I've used Victron LiFePO4 'smart' batteries previously - expensive but reliable.  They have a Bluetooth app server built in.  100Ah weighed about 10kg.

I've also used second hand Valance batteries which show up on eBay fairly often.  These are fantastic!  The BMS is built in - you just treat it like a car battery.  When the battery is rated for over thousands of 100% charge discharge cycles (which you rerely do in a car), being second hand barely affects the life expectancy.  I paid £300 for the last 100Ah Valance battery.

[landroversforever]

Thanks Si, helpful info! and a useful weight saving! And they'd give the sort of output a 3L diesel would need on the starter or a sensible (not a gigglepin etc) winch would draw? 

Would they then warrant using an even higher rated alternator? or just able to use more of what's there? 

[FridgeFreezer]

For a starter battery a stock dumb lead acid still feels hard to beat, but for them folks with fancy 24v winch setups and whatnot I guess if you've thrown that much money into it a couple of grand on a really good battery pack is very viable and likely a worthwhile performance boost - and lighter than a pile of lead-acid ones.

I saw a truck not long ago with a big 24v setup, about 10k worth of Gigglepin bolted to the front, another one in the back, and 4 big Odyssey's sat in the tray... looked expensive AND heavy.

[Ed Poore]

3 hours ago, FridgeFreezer said:

I saw a truck not long ago with a big 24v setup, about 10k worth of Gigglepin bolted to the front, another one in the back, and 4 big Odyssey's sat in the tray... looked expensive AND heavy.

Makes you wonder if they'd be better off with hydraulic... I know it doesn't work when the engine is off but keeps on pulling in all other aspects.

[Nonimouse]

On 9/27/2022 at 8:29 PM, Ed Poore said:

Makes you wonder if they'd be better off with hydraulic... I know it doesn't work when the engine is off but keeps on pulling in all other aspects.

Electro-hydraulic back up is viable and uses less electricity. First four used to sell a nice in tank pump - bascially a Bow 1

[Ed Poore]

2 hours ago, Nonimouse said:

Electro-hydraulic back up is viable and uses less electricity. First four used to sell a nice in tank pump - bascially a Bow 1

I did think that as well but don't agree with your uses less electricity comment.

Hydraulics at best are usually about 80% efficient if you really really work at it. Electric motors these days are usually pushing 80% efficient at a minimum, they can be much more. The drives are closing in on 100% (although they'll never achieve it but they're getting damn close).

[Nonimouse]

56 minutes ago, Ed Poore said:

I did think that as well but don't agree with your uses less electricity comment.

Hydraulics at best are usually about 80% efficient if you really really work at it. Electric motors these days are usually pushing 80% efficient at a minimum, they can be much more. The drives are closing in on 100% (although they'll never achieve it but they're getting damn close).

I was quoting form the manufacturer

[FridgeFreezer]

The laws of thermodynamics would suggest electric -> hydro -> mechanical can't be as a efficient as directly going electric->mechanical or hydro->mechanical, although a well set-up electric hydraulic pump would probably be a much more stable and controlled electrical load than the average monkey with an electric winch and their finger on the trigger until smoke comes off the cables.

[Nonimouse]

25 minutes ago, FridgeFreezer said:

 although a well set-up electric hydraulic pump would probably be a much more stable and controlled electrical load than the average monkey with an electric winch and their finger on the trigger until smoke comes off the cables.

Can't argue with that

[Daan]

All far too complicated; getting power from the engine to the winch through a hydraulic pump, motor and tank, or via alternator, battery's and motors all add weight and complexity.

All you need is a PtO on your transfer box and a shaft.

[Nonimouse]

53 minutes ago, Daan said:

 

All you need is a PtO on your transfer box and a shaft.

Until the engine stops - which is where this came from